In situ electro-organic synthesis of hydroquinone using anisole on MWCNT/Nafion modified electrode surface and its heterogeneous electrocatalytic reduction of toxic Cr(vi) species.

Owing to its electro-inactive character, anisole (phenylmethyl ether, PhOCH3) and its related derivatives have been used as electrolytes in electrochemistry. Herein, we report a simple one-step electro-organic conversion of PhOCH3 to hydroquinone (HQ) on a pristine-MWCNT-Nafion modified electrode glassy carbon electrode surface, GCE/Nf-MWCNT@HQ, in pH 2 KCl-HCl solution within 15 min of working time. The chemically modified electrode showed a highly redox-active and well-defined signal at an apparent standard electrode potential, E o' = 0.45 V vs. Ag/AgCl (A2/C2) with a surface excess value, Γ HQ = 2.1 × 10-9 mol cm-2. The formation of surface-confined HQ is confirmed by collective physicochemical and spectroscopic characterizations using TEM, UV-Vis, Raman, FTIR, NMR and GC-MS techniques and with several control experiments. Consent about the mechanism, the 2.1% of intrinsic iron present in the pristine-MWCNT is involved for specific complexation with oxygen donor organic molecule (PhOCH3) and hydroxylation in presence of H2O2 (nucleophilic attack) for HQ-product formation. The GCE/Nf-MWCNT@HQ showed an excellent heterogeneous-electrocatalytic reduction of Cr(vi) species in acidic solution with a linear calibration plot in a range, 5-500 ppm at an applied potential, 0.4 V vs. Ag/AgCl with a detection limit, 230 ppb (S/N = 3; amperometric i-t). As a proof of concept, selective detection of toxic Cr(vi) content in the tannery-waste water has been demonstrated with a recovery value ∼100%.

Facile Electrochemical Demethylation of 2-Methoxyphenol to Surface-Confined Catechol on the MWCNT and Its Efficient Electrocatalytic Hydrazine Oxidation and Sensing Applications.

Owing to its biological significance, preparation of stable surface-confined catechol (CA) is a long-standing interest in electrochemistry and surface chemistry. In this connection, various chemical approaches such as covalent immobilization (using amine- and carboxylate-functionalized CA, diazotization-based coupling, and Michael addition reaction), self-assembled monolayer on gold (thiol-functionalized CA is assembled on the gold surface), CA adsorption on the ad-layer of a defect-free single-crystal Pt surface, π-π bonding, CA pendant metal complexes, and CA-functionalized polymer-modified electrodes have been reported in the literature. In general, these conventional methods are involved with a series of time-consuming synthetic procedures. Indeed, the preparation of a surface-fouling-free surface-confined system is a challenging task. Herein, we introduce a new and facile approach based on electrochemical demethylation of 2-methoxyphenol as a precursor on the graphitic surface (MWCNT) at a bias potential, 0.5 V vs Ag/AgCl in neutral pH solution. Such an electrochemical performance resulted in the development of a stable and well-defined redox peak at E o' = 0.15 (A2/C2) V vs Ag/AgCl within 10 min of preparation time in pH 7 phosphate buffer solution. Calculated surface excess (16.65 × 10-9 mol cm-2) is about 10-1000 times higher than the values reported with other preparation methods. The product (catechol) formed on the modified electrode was confirmed by collective electrochemical and physicochemical characterizations such as potential segment analysis, TEM, Raman, IR, UV-vis, GC-MS, and NMR spectroscopic techniques, and thin-layer chromatographic studies. The electrocatalytic efficiency of the surface-confined CA system was demonstrated by studying hydrazine oxidation and sensing reactions in a neutral pH solution. This new system is found to be tolerant to various interfering biochemicals such as uric acid, xanthine, hypoxanthine, glucose, nitrate, hydrogen peroxide, ascorbic acid, Cu2+, and Fe2+. Since the approach is simple, rapid, and reproducible, a variety of surface-confined CA systems can be prepared.

Silver nanoparticles engineered by thermal co-reduction approach induces liver damage in Wistar rats: acute and sub-chronic toxicity analysis.

Recently, nanotechnology applications have increased tremendously in consumer products. However, it has been observed that these nanoparticles can cause a potential risk to the environment as well as human health. In the present manuscript, we have analyzed acute and sub-chronic toxicity of engineered silver nanoparticles (AgNPs) by assessing the impact on Wistar rats. AgNPs were synthesized by a novel approach-thermal co-reduction-with spherical shape and a uniform size distribution of 60 nm. The estimated LD50 value was observed to be more than 2000 mg/kg bw in acute toxicity studies. Sub-chronic toxicity indicated impairment of liver and kidney enzymes and various hematological and biochemical parameters. Tissue distribution studies indicated the target organ for accumulation is liver after treatment with AgNP. Particle deposition and congestion was observed in major organs-though, and heart and pancreatic tissues were not affected even by the higher doses. On the basis of the observations of this study, it is concluded that up to 40 mg/kgbw is a safer dose of AgNPs (60 nm, engineered by thermal co-reduction approach) and further research will be required to validate the long-term accumulation in body. In addition, it can also be considered by policymakers for the safer use of AgNPs.

In Situ Immobilized Sesamol-Quinone/Carbon Nanoblack-Based Electrochemical Redox Platform for Efficient Bioelectrocatalytic and Immunosensor Applications.

Most of the common redox mediators such as organic dyes and cyanide ligand-associated metal complex systems that have been used for various electrochemical applications are hazardous nature. Sesamol, a vital nutrient that exists in natural products like sesame seeds and oil, shows several therapeutic benefits including anticancer, antidiabetic, cardiovascular protective properties, etc. Herein, we introduce a new electrochemical redox platform based on a sesamol derivative, sesamol-quinone (Ses-Qn; oxidized sesamol), prepared by the in situ electrochemical oxidation method on a carbon nanoblack chemically modified glassy carbon electrode surface (GCE/CB@Ses-Qn) in pH 7 phosphate buffer solution, for nontoxic and sustainable electrochemical, electroanalytical, and bioelectroanalytical applications. The new Ses-Qn-modified electrode showed a well-defined redox peak at E o = 0.1 V vs Ag/AgCl without any surface-fouling behavior. Following three representative applications were demonstrated with this new redox system: (i) simple and quick estimation of sesamol content in the natural herbal products by electrochemical oxidation on GCE/CB followed by analyzing the oxidation current signal. (ii) Utilization of the GCE/CB@Ses-Qn as a transducer, bioelectrocatalytic reduction, and sensing of H2O2 after absorbing the horseradish peroxidase (HRP)-based enzymatic system on the underlying surface. The biosensor showed a highly selective H2O2 signal with current sensitivity and detection limit values 0.1303 µA µM-1 and 990 nM, respectively, with tolerable interference from the common biochemicals like dissolved oxygen, cysteine, ascorbic acid, glucose, xanthine, hypoxanthine, uric acid, and hydrazine. (iii) Electrochemical immunosensing of white spot syndrome virus by sequentially modifying primary antibody, antigen, secondary antibody (HRP-linked), and bovine serum albumin on the redox electrode, followed by selective bioelectrochemical detection of H2O2.

A phase II, single-arm, open-label, multicenter study to evaluate the efficacy and safety of P276-00, a cyclin-dependent kinase inhibitor, in patients with relapsed or refractory mantle cell lymphoma.

INTRODUCTION: Overexpression of cyclin D1 is a hallmark feature of mantle cell lymphoma (MCL). Many of the oncogenic effects of cyclin D1 are mediated through cyclin-dependent kinases (CDKs). P276-00 is a potent small molecule inhibitor of CDK4-D1, CDK1-B, and CDK9-T, with promising activity in preclinical models. In phase I studies of P276-00 in patients with refractory solid neoplasms, it was well-tolerated with a mild trend toward single-agent efficacy. PATIENTS AND METHODS: A phase II study of P276-00 was conducted in patients with relapsed or refractory MCL at the recommended dose of 185 mg/m(2)/day from days 1 to 5 of a 21-day cycle. Thirteen patients were enrolled in the present study. RESULTS: Of the 13 patients, 11 experienced disease progression, 1 patient was withdrawn because of an adverse event (AE), and 1 patient died. Also, 11 patients (84.6%) experienced a treatment-emergent AE deemed related to P276-00. Of the 13 patients, 9 (69.2%) received ≥ 2 cycles of treatment, which was the predefined threshold to be evaluable for efficacy. Treatment was discontinued early in 2 patients because of AEs (1 of which was attributed to P276-00 administration) and in 2 patients because of disease progression. Finally, 2 patients experienced stable disease for an estimated median duration of 60.5 days (range, 58-63 days). The estimated median time to progression for the predefined efficacy population was 43 days (range, 38-58 days). CONCLUSION: Given the results observed in the present study, if evaluation of CDK inhibition in MCL continues, it should be considered earlier in the disease course or as a part of combination strategies for relapsed or refractory disease.

Revision of QSAR, docking, and molecular modeling studies of anti-influenza virus A (H1N1) drugs and targets: analysis of hemagglutinins 3D structure.

Recently WHO and NREVSS collaborating laboratories located in all 50 states, and Washington D.C reported that out of 3,588 specimens,164 were found positive for influenza type (i.e. 4.6%) and from these 164 specimens 162 (i.e. 98.8 %) were of influenza A H1N1 subtype. Comparative study of the past and current reports gives a general idea that the influenza activity deserves high attention from public health authorities in the U.S. In this connection, presently some groups are developing intensive computer-aided research in QSAR, Docking, Molecular Modeling and Drug Design, Sequence Analysis and Phylogenetic analysis of candidate compounds and/or targets; in order to advance in the treatment and/or prevention of this pandemic Flu. In this work, primarily we carry out a mini-review of the more important theoretical studies reported until now within this area, followed by the study of a specific type of target. Keeping in view the nature of this virus, we can conclude that there is always a need to find other target protein as inhibitor other than the existing one. So that this lethal pandemic flu can be treated and prevented further. Therefore, after Neuraminidase and M2 ion channels the surface protein that we can target in H1N1 strain is Hemagglutinins (HA). We use comparative modeling; which is one of the methods that can reliably generate a 3D model for HA protein. Multiple structures of this subtype of Influenza Virus are available at PDB, but we are focused on Influenza A (H1N1). Therefore, methodology of analysis mainly focuses on modeling the structure of this protein and, if possible, finding a probable active sites and inhibitors to it.